1. Field of the Invention
The invention relates to a siphoning device having particular utility as a "food baster," but also lending itself for use as a device for medical, scientific and industrial applications. The device can be used for the separation of immiscible liquids. The device can further be used for withdrawal of a measured or unmeasured amount of liquid from a container in one location, storage of the liquid during transportation and deposit of the liquid in a container at a remote location. The device uses a combination of an air valve and a liquid valve.
2. Brief Description of the Prior Art
The devices commonly known as basters do not effectively contain the liquid which has been drawn into the device. Typically these devices expel some of whatever liquid the user is attempting to move before the device has reached the final destination.
The term baste is used in the application consistent with the definition in the American Heritage Dictionary, Third Edition, Copyright 1994, InfoSoft International, as follows:
baste tr.v. basted, basting, bastes.
To moisten (meat, for example) periodically with a liquid, such as melted butter or a sauce, especially while cooking. baster n.
In its simplest form (hereinafter referred to as the `simple baster`) the simple baster consists of only two parts. The first part is the bulb, which is typically made of rubber or a rubber-like plastic. The bulb is generally thick and soft to allow for flexibility as the device is operated by squeezing and releasing the bulb by hand. The second part is a hollow round tube or cylinder, tapered at one end to a small opening. The bulb is attached to the tube at the wider end, with the small opening being used to collect and disperse liquids. While baking meat, to add flavoring and prevent dehydration, it is desirable to take broth or meat juices to baste the meat. The baster is employed in this endeavor by holding the device in one hand and ejecting some of the air from the bulb. The lower end of the tube is placed below the liquid surface, the bulb is released and the vacuum draws the liquid into the tube. The tube is then moved to the top of the meat being cooked, the bulb is squeezed and the liquid is ejected over the meat. In the simple baster, when the liquid is drawn into the tube, it is frequently hot. The hot liquid heats the air in the tube and the bulb, causing expansion of the air. The expansion of the air forces at least some of the liquid out the tube. It is often impossible to draw or retain enough liquid in the baster to adequately baste the meat. Attempts to contain the liquid by turning the tube over, bulb end down, can leak hot liquid in an uncontrollable and dangerous fashion. Turning the baster all the way places the bulb, filled with hot liquid, near the user's hand and may cause burns through the flexible bulb.
Another way the simple baster is often used is to separate the meat juices into their component lighter fat and heavier water-soluble parts. When separated from the fat, the heavier water-soluble material is frequently used as a component in gravies. The heavier materials will be referred to as `flavorings`. While it would be desirable to wait for a brief time for the fat and flavorings to separate, for distribution into different containers, this is not always feasible. The nature of the simple baster is not well suited for use as a separator because the contents begin to exit as soon as they have entered, often with outside air bubbling through and remixing the liquids to be separated. Any attempts to draw all the pan juices into the baster for separating in one operation results in mixing the pan juices, just the opposite of the desired separation.
Among the problems encountered in the simple baster is the inability to prevent the liquid from dripping out due to simple gravity. Further, the heat of the air trapped above the liquid, in both the tube and bulb, drives the liquid out of the baster in an uncontrolled manner.
Another shortcoming of the simple baster is the inability to measure or control the exact amount of liquid delivered by the baster. The only control over the volume entering the tube occurs when the bulb is squeezed a particular amount or the inlet pulled out of the liquid. The user must estimate how much to squeeze the bulb prior to insertion into the liquid, since squeezing the bulb after the tube has been partially filled drives the liquid out of the baster. Thus, the device cannot be operated in a cumulative manner.
The simple baster, or a similar device, can also be used for a multitude of tasks that involve moving liquids. These liquids can be hot or cold, acid or base, aqueous or not, highly fluid or partially viscous.
Small versions of the prior art simple baster, such as the medicine dropper, generally operate as intended. Volatile solutions, however can generate vapor pressure sufficient to force the liquid from the tube. Due to the small amount of liquid, the capillary action and/or surface tension, are sufficient to allow the dropper to retain the liquid until it is dispensed. As the medicine dropper is enlarged to the size of the simple baster, the flaws of the design appear.
Capillary action, as used herein, refers to the force that results from greater adhesion of a liquid to a solid surface than internal cohesion of the liquid itself. This action causes the liquid to be raised against a vertical surface, as water is in a clean glass tube. Surface tension, as used herein, refers to a property of liquids arising from unbalanced molecular cohesive forces at or near the surface. As a result, the surface tends to contract and has properties resembling those of a stretched elastic membrane.
In summary, the prior art simple basters are deficient in at least four ways:
1. Fluid leaks due to flow under the force of gravity.
2. When hot liquid is used, air above the liquid expands and pushes the liquid out, making the handling of liquids difficult and dangerous.
3. The amount of liquid that can be drawn up is limited by the size of the bulb and the air trapped within the bulb.
4. Making exact liquid measurements are difficult, because of leaking of the device and the inability to control the amount of liquid drawn into the device.